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The energy markets are currently under tremendous pressure caused by instability in fuel prices and environmental issues. Thecitizens are affected by the constant increase in fuel prices, threat to the security of energy supply and by climate change resultingfrom an environmental policy neglectedSo, cogeneration systems arise as a way of producing high efficiency energy, lower environmental impacts, and a decrease in theconsumption of primary energy. However, cogeneration, to date recognized as one of the most efficient ways of producingelectricity and thermal energy, has seen its future in jeopardy because of the recent austerity policies which have decreased theremuneration regarding the electricity produced.The objective of this work is the approach to the new legal framework applicable to the cogeneration activity in Portugal. In thatway, an energy audit was done based on an existing cogeneration plant. A comparison of the results obtained by applying the newlegal framework with the results obtained by previous legislation was carried out. The avoided CO2 emissions were comparedwith separate heat and electricity production. A sensitive economic analysis was carried out in function of the prices of electricity,fuel and cost investment.

The use of decentralized Combined Heat and Power (CHP) plants is increasing since the high levels of efficiency they can achieve. Thus, to determine the optimal operation of these systems in dynamic energy-market scenarios, operational constraints and the time-varying price profiles for both electricity and the required resources should be taken into account. In order to maximize the profit during the operation of the CHP plant, this paper proposes an optimization-based controller designed according to the Economic Model Predictive Control (EMPC) approach, which uses a non-constant time step along the prediction horizon to get a shorter step size at the beginning of that horizon while a lower resolution for the far instants. Besides, a softening of related constraints to meet the market requirements related to the sale of electric power to the grid point is proposed. Simulation results show that the computational burden to solve optimization problems in real time is reduced while minimizing operational costs and satisfying the market constraints. The proposed controller is developed based on a real CHP plant installed at the ETA research factory in Darmstadt, Germany. ; Authors would like to thank Ikergune (Exte-Tar Group), the project IKERCON (Ref. c-10683) and the FI-AGAUR scholarship of the Catalan government for their scientific support in this work. Besides, parts of this work are funded by the German Federal Ministry of Education and Research (BMBF) in the project SynErgie and the German Federal Ministry of Economic Affairs and Energy (BMWi) in the project PHI-Factory.

Many production processes work with on-site Combined Heat and Power (CHP) systems to reduce their operational cost and improve their incomes by selling electricity to the external grid. Optimal management of these plants is key in order to take full advantage of the possibilities offered by the different electricity purchase or selling options. Traditionally, this problem is not considered for small cogeneration systems whose electricity generation cannot be decided independently from the main process production rate. In this work, a non-linear gray-box model is proposed in order to deal with this dynamic optimization problem in a simulated sugar factory. The validation shows that with only 52 equations, the whole system behavior is represented correctly and, due to its structure and small size, it can be adapted to any other production process working along a CHP with the same plant configuration.

Trabajo presentado en el 9th IFAC Conference on Manufacturing Modelling, Management and Control (MIM); celebrada en Berlín (Alemania), del 28 al 30 de agosto de 2019 ; The use of decentralized Combined Heat and Power (CHP) plants is increasing since the high levels of efficiency they can achieve. Hence, to determine the optimal operation of these systems in the changing energy market, the time-varying price profiles for both electricity as well as the required resources and the energy-market constraints should be considered into the design of the control strategies. To solve these issues and maximize the profit during the operation of the CHP plant, this paper proposes an optimization-based controller, which will be designed according to the Economic Model Predictive Control (EMPC) approach. The proposed controller is designed considering a non-constant time step to get a high sampling frequency for the near instants and a lower resolution for the far instants. Besides, a soft constraint to met the market constraints for the sale of electric power is proposed. The proposed controller is developed based on a real CHP plant installed in the ETA research factory in Darmstadt, Germany. Simulation results show that lower computational time can be achieved if a non-constant step time is implemented while the market constraints are satisfied. ; Authors would like to thank the FI-AGAUR scholarship of the Catalan Government and the project IKERCON ref. c10683 for their financial and scientific support in this work, respectively. Besides, parts of this work are funded by the German Federal Ministry of Education and Research (BMBF) in the project SynErgie and the German Federal Ministry of Economic Affairs and Energy (BMWi) in the project PHI-Factory.

Solar energy has a significant potential for future power generation but its intermittent and variable nature results in fluctuations of the operational performance of solar power plants. Despite thermal energy storage (TES) systems improving the flexibility and the sustainability of the performance of Concentrated Solar Power (CSP) plants, smart management is required to deal with the complex dynamic variations in the behaviour and interaction of the different plant's subsystems. In this paper, the design, manufacture, and validation of a smart control unit with extended capabilities for a small-scale CSP combined heat and power (CHP) system are described. More precisely, the control unit has been designed to control and optimise the operation of a microscale Organic Rankine Cycle (ORC) unit coupled with Linear Fresnel Reflectors solar field and an advanced latent heat thermal energy storage tank which were developed by a consortium of universities and companies in the framework of the EU-funded project 'Innova Microsolar'. In parallel to the designing and building the smart control unit, an advanced simulator has been developed in Matlab/Simulink® to investigate the performance of the plant for a wide range of varying ambient and operating conditions. The simulation framework has been connected to the real control unit according to a hardware-in-the-loop (HiL) approach to optimise the control logic of the integrated plant to overcome potential technical and reliability issues during the commissioning of the plant. The developed hardware and the proposed scientific approach can be extended to a wide range of complex solar energy systems equipped with TES and to be integrated into the built environment. ; This study is a part of the Innova Microsolar Project, funded in the framework of the European Union's Horizon 2020 Research and Innovation Programme (Grant Agreement No 723596). The authors at the University of Lleida would like to thank the Catalan Government for the quality accreditation given to their ...

Nowadays, ever-increasing energy demands and the depletion of fossil fuels require efficient and environmentally friendly technologies for energy generation. In this context, energy systems integration makes for a very strong proposition since it results in energy saving, fuel diversification, and the supply of cleaner energy. To this end, it is of the utmost importance to realize the current developments in this field and portray the state of the art of renewable generation in integrated energy systems. This review evaluates the utilization of bioenergy in cogeneration and trigeneration systems. The statistical reports of bioenergy and combined heat and power deployments in 28 countries of the European Union are discussed. Then, the most common research objectives of biomass-fueled combined heat and power systems are classified into three primary performance analyses, namely, energy and exergy analysis, thermo-economic optimization, and environment assessment. The influencing parameters of biomass utilization on each type of assessment are discussed, and the basic principles for carrying out such analyses in energy systems are explained. It is illustrated that the properties of feedstock, selection of appropriate conversion technology, associated costs with the biomass-to-bioenergy process, and sustainability of biomass are the primary influencing factors that could significantly affect the results of each assessment.

Nowadays, ever-increasing energy demands and the depletion of fossil fuels require efficient and environmentally friendly technologies for energy generation. In this context, energy systems integration makes for a very strong proposition since it results in energy saving, fuel diversification, and the supply of cleaner energy. To this end, it is of the utmost importance to realize the current developments in this field and portray the state of the art of renewable generation in integrated energy systems. This review evaluates the utilization of bioenergy in cogeneration and trigeneration systems. The statistical reports of bioenergy and combined heat and power deployments in 28 countries of the European Union are discussed. Then, the most common research objectives of biomass-fueled combined heat and power systems are classified into three primary performance analyses, namely, energy and exergy analysis, thermo-economic optimization, and environment assessment. The influencing parameters of biomass utilization on each type of assessment are discussed, and the basic principles for carrying out such analyses in energy systems are explained. It is illustrated that the properties of feedstock, selection of appropriate conversion technology, associated costs with the biomass-to-bioenergy process, and sustainability of biomass are the primary influencing factors that could significantly affect the results of each assessment.

"This book provides an analysis of the European policy approach to combined heat and power (CHP), a highly efficient technology used by all EU Member States for the needs of generating electricity and heat. European Law on Combined Heat and Power carries out an assessment of the European legal and policy measures on CHP, evaluating how it has changed over the years through progress and decline in specific member states. Over the course of the book, Sokołowski explores all aspects of CHP, examining the types of measures used to steer the growth of cogeneration in the EU and the policies and regulatory tools that have influenced its development. He also assesses the specific role of CHP in the liberalisation of the internal energy market and EU action on climate and sustainability. Finally, by delivering his notions of 'cogenatives', 'cogenmunities', or 'Micro-Collective-Flexible-Smart-High-Efficiency cogeneration', Sokołowski considers how the new EU energy package - 'Clean energy for all Europeans' - will shape future developments. This book will be of great interest to students and scholars of energy law and regulation, combined heat and power and energy efficiency, as well as policy makers and energy experts working in the CHP sector"--

Heat demand is a large contributor to greenhouse gas (GHG) emissions in the European Union (EU), as heat is largely produced using fossil fuel resources. Extended use of district heating (DH) could reduce climate impact, as DH systems can distribute heat produced in efficient combined heat and power (CHP) plants and industrial excess heat, thus utilising heat that would otherwise be wasted. The difficulty to estimate and compare GHG emissions from DH systems can however constitute an obstacle to an expanded implementation of DH. There are several methods for GHG emission assessments that may be used with varying assumptions and system boundaries. The aim of this paper is to illuminate how methodological choices affect the results of studies estimating GHG emissions from DH systems, and to suggest how awareness of this can be used to identify possibilities for GHG emission reductions. DH systems with CHP production and industrial excess heat are analysed and discussed in a systems approach. We apply different methods for allocating GHG emissions between products and combine them with different system boundaries. In addition, we discuss the impact of resource efficiency on GHG emissions, using the framework of industrial symbiosis (IS). We conclude that assessments of the climate impact of DH systems should take local conditions and requirements into account. In order for heat from CHP production and industrial excess heat to be comparable, heat should be considered a by-product regardless of its origin. That could also reveal opportunities for GHG emission reductions. ; This paper was written under the auspices of the Energy Systems Programme, which is financed by the Swedish Energy Agency. Dr Sandra Backlund, Swedish Environmental Protection Agency, is gratefully acknowledged for valuable input to an early version of the paper. We would also like to thank two anonymous reviewers for helpful comments.

An introduction and overview from a larger report about the partnership between the Environmental Protection Agency and Combined Heat and Power (CHP) stakeholders, including CHP Industry, state and local governments, energy users, etc., in an effort to promote biomass as an alternative energy resource.

With the complicated problems faced by The State Electricity Company (PLN)nowadays, the writer would support analyzing for solving problem with the Assessment for Combined Heat and Power (CHP) in Indonesia. CHP Technology/Cogeneration is a technology not produce carbon, so this technology will help Government Policy for reducing carbon emission and environment sustainability. This project has done together among BPP Teknologi (Directorate KKE and UPT LSDE) and Ciptakarya Hasta Paramita Cooperative with Grant budget from UNDP-GEF and supporting budgetDIP.

I det nuværende danske energisystem bliver hoveddelen af den benyttede el og varme produceret på et kraftvarmeværk (KVV). Med stadig større produktion af el fra vedvarende energikilder bliver det en stadig større udfordring at tilpasse el og varmeproduktion til behovsprofilet, da produktions kapacitetens tekniske restriktioner begrænser den effektive produktion på KVV. Varmepumper (VP) kan benyttes til at afkoble sådanne begrænsninger, men den nuværende teknologi er ikke konkurrencedygtig. Metoder til at forbedre energi effektiviteten er nødvendige, for at kunne opnå de politisk fremlagte mål for CO2-emmisioner. Det præsenterede studie undersøger den mulige introduktion af VP fra både et termodynamisk- og system/operationsanalyse perspektiv, for at finde optimale integrations løsninger for både nutidige og fremtidige energisystemer. Fem generiske konfigurationer for VP i fjernvarme- (FV) systemer blev identificeret og sammenlignet ud fra en termodynamisk analyse. Den operative præstationsevne af konfigurationerne blev undersøgt både for den enkelte enhed og fra et system perspektiv for forskellige FV temperaturer, forskellige drivmidler og ved systemer med forskellige produktions teknologier i FV netværket. Analysen viste at tre konfigurationer er særligt fordelagtige, hvorimod de to tilbageværende konfigurationer, set fra et system perspektiv, præsterer tilsvarende eller endog dårligere end det der kan forventes af en elektrisk vandvarmer. Den ene af de tre fordelagtige konfigurationer skal lokaliseres hos forbrugeren, hvorimod de to resterende kan placeres på lokaliteter med særligt gunstige temperaturer, hvor FV netværket benyttes til at distribuere varmen. En stor mængde operative og økonomiske restriktioner begrænser anvendelsen af VP som benytter naturlige arbejdsmedier, hvilket kan være de eneste mulige valg for Danske forhold. Begrænsningerne er meget afhængige af integrationen af energistrømmene for varme kilde og dræn. En vurdering af fordelagtige operative anlæg blev udført ud fra restriktioner som tilgængeligt køleteknisk udstyr og behovet for en positiv nutidsværdi for investeringen. Seks kompressions varme pumper (KVP) blev analyseret sideløbende med ammoniak-vand hybrid absorption kompressions varme pumpe (HAKVP), hvilket korresponderer til en øvre begrænsning i dræn temperature op til 150 °C. Den bedste disponible teknologi blev bestemt for hver mulig kombination af kilde og dræn temperaturer. Resultaterne viste at fem forskellige VP systemer fremsætter den bedste tilgængelige teknologi ved forskellige dele af det samlede arbejdsområde. Ammoniak-vand HAKVP og ammoniak KVP systemer med enten lav eller højtrykskomponenter er fordelagtige for en meget stor del af de analyserede dræn temperaturer og temperaturløft. Krav til dræn temperaturer og temperaturløft kan ikke tilfredsstilles for mange FV systemer hvis VP varmer til fremløbstemperaturen, med de benyttede økonomiske begrænsninger inkluderet i analysen. Den specifikke ydeevne for to FV VP konfigurationer blev undersøgt i yderligere detalje, hvortil der benyttes endelige temperatur niveauer som svarer til en række typiske FV netværk. Otte systemer blev analyseret for deres anvendelighed, og systemerne blev optimeret til hvert driftspunkt ved brug af exergoøkonomisk analyse. De enkelte VP blev sammenlignet baseret på prisen af den producerede varme. Resultaterne viser, at de tekniske begrænsninger medfører en betydeligt forøget pris på varme ved høje FV temperaturer, sammenlignet med den mest konkurrencedygtige termodynamiske kredsproces. Ved høje og mellemhøje temperaturløft er det muligt at opnå en kredsproces effektivitet på op til 45-50 % af det teoretisk mulige (i forhold til Lorenz processen), hvorimod så lave virkningsgrader som 36 % må forventes for lave temperaturløft. Tre typisk anvendte operations analyse metoder blev analyseret for deres påvirkning på driftsstyring for energiteknologier. Ved at fokusere på den fysiske repræsentation af KVV, synes det klart at den simple repræsentation tillader ugennemførlig produktion. Når blandet heltals programmering (BHP) og ikke lineær programmering (ILP) benyttes, bliver antallet af driftstimer og produktionen af varme fra VP betydeligt forøget, da VP kan benyttes til at udligne driftsprofilet for KVV i energisystemer med betydelige tekniske begrænsninger. En BHP energi system model blev udviklet, med fokus på detaljeret repræsentation af KVV og VP. To energiscenarier blev benyttet til analysen, et nuværende, som er valideret for året 2011, og et fremtidigt scenarie, som modsvarer det energiplanlæggere foreslår for 2025, hvor reduktioner af CO2-emissioner er en særlig indsats. Den ændrede drift for elektricitets produktions enheder fører til genovervejelse af optimum for FV netværks temperaturer, for at opnå den laveste pris og de laveste CO2-emissioner. Den udviklede energisystem model blev benyttet til at analysere den ændrede produktion. Produktions ændringer fra typiske KVV teknologier blev benyttet til at repræsentere den ændrede produktion af el og varme for ændrede FV temperaturer. Resultaterne viser at forbruget af primær energi og systemets omkostninger kan reduceres med ca. 5-7 % ved FV fremløbstemperaturer på 60 til 70 °C for 2025 scenariet. Yderligere reduktion i FV temperaturer resulterer i modsat rettede tendenser, da varmt brugsvand skal benytte stadig større mængder el for at opnå de nødvendige temperaturer. Resultaterne er netværks specifikke, da de repræsenterer specifikke FV forsyningsværker og netværk restriktioner, men tilsvarende tendenser kan forventes for andre store FV netværker. ; In the current Danish energy system, the majority of electricity and heat is produced in combined heat and power (CHP) plants. With increasing shares of intermittent renewable power production, it becomes a challenging task to match power and heat production to its demand curves, as production capacity constraints limit the efficient operation of the CHP plants. Heat pumps (HPs) can be used to decouple such constraints, but current state of the art are not competitive all things considered. Methods to improve the high energy efficiency are required to match the politically agreed carbon emission goals. The presented study investigates the possible introduction of HPs from both a thermodynamic and a system/operation management perspective, in order to find optimal integration schemes in both current and future energy scenarios. Five generic configurations of HPs in district heating (DH) systems were identified and compared based on a thermodynamic analysis. The operational performance of the configurations were investigated at both local and system level considering different DH network temperatures, different fuels and different production technologies in the DH network. The analysis show that three configurations are particular advantageous, whereas the two remaining configurations result in system performance close to or below what may be expected from an electric heater. One of the three advantageous configurations is required to be positioned at the location of the heat demand, whereas the two remaining can be located at positions with availability of high temperature sources by utilising the DH network to distribute the heat. A large amount of operational and economic constraints limit the applicability of HPs operated with natural working fluids, which may be the only feasible choice in Danish conditions. The limitations are highly dependent on the integration of heat source and sink streams. An evaluation of feasible operating conditions was carried out considering the constraints of available refrigeration equipment and a requirement of a positive net present value of the investment. Six vapour compression heat pump (VCHP) systems were considered along with the ammonia-water hybrid absorption compression heat pump (HACHP), corresponding to an upper limit of the sink temperature of up to 150 °C. The best available technology was determined for each set of heat sink and source temperatures. The results showed that five different HP systems propose the best available technology at different parts of the complete domain. Ammonia-water HACHP and ammonia VCHP systems utilising either low or high pressure components are preferable very broad range of sink temperature and temperature lifts. With the considered economic constraints in place, the requirements in terms of sink temperatures and temperature lift are not met for many DH networks considering the configurations which heat to forward temperatures. The specific performance for two DH HP configurations were studied in detail, using the finite temperature levels of a range of common DH networks. Eight systems were examined in terms of applicability, and the systems were optimised for each operating condition using exergoeconomic theory. The HPs were compared based on cost of heat. The results show that including the practical applicability of components causes a significantly increased cost at high temperature lifts, compared to the most competitive thermodynamic cycle. At high and medium temperature lifts cycle efficiencies of 45 - 50 % of the theoretical maximum (Lorenz cycle limit) can be achieved, whereas for low temperature lifts, efficiencies as low as 36 % may be expected. Three frequently used operation optimisation methods were examined, in order to investigate their impact on operation management of energy system technologies. By focussing on the physical representation of a CHP-plant, it is clear that a simple representation allows infeasible production. Using MIP or NLP optimisation, the number of operation hours and the total production of heat from HPs are significantly increased, as the HPs may be used to shave the load patterns of CHP units in significantly constrained energy systems. A MIP energy system model was developed with focus on the detail level of features for representation of CHP and HP units. Two energy scenarios were considered, one current, which is a validated model for 2011, and a future scenario, as proposed by energy planners for 2025, where reductions in carbon emissions for heat is of major interest. The changed distribution of electricity generation technologies may suggest a reconsideration of optimum for DH network temperatures, in order to achieve low cost and minimum carbon emissions. The developed energy system model was used to investigate the changed operation. Production curves from typical CHP-plant technologies were used to represent the changed power and heat production for changed DH temperatures. The results show that both primary fuel consumption and cost can be reduced approximately 5-7 % at DH forward temperatures of 60 - 70 °C in 2025 scenario. Further reduction results in contrary tendencies as hot tap water requires increasing amounts of electricity to reach required temperatures. The results are network specific, as they represent the specific DH utility technologies and network constraints, but similar trends can be expected for other large DH networks.

The main objective of this work is to develop a software tool to perform an techno-economic feasibility analysis of cogeneration systems for electricity and heat production, based on fuel cell technology (FC-CHP). The software tool should provide useful information to the decision makers. Moreover, the developed software will be applied to specific case studies to obtain the main indicators of the economic viability of the system. A FC-CHP system is a technology with potential to change the current paradigm, which consists in obtaining electricity from the power grid and, separately, heat through gas boilers. The method developed in this study allows to carry out a viability analysis over a specific time horizon, based on technical and economic parameters, to size the FC-CHP system and to adapt the calculations to the market conditions of each case study. It is important to consider the market conditions, because the previous works found in the literature remark that the viability of the FC-CHP technology depends on specific factors that vary by country and region. Local economic factors include government policies to support new technologies of distributed generation, that is, generation of electricity at or near where it will be used. Another local factor is the difference in prices between natural gas and electricity ("spark spread"), and the expected evolution of these prices. From the environmental point of view, the composition of the country's power generation mix has influence on the emissions reduction using FC-CHP. The pattern of thermal and electrical energy demand of each specific case also influence, and the relative amount of each one (heat-to-power ratio). The method developed requires a source of energy consumption data, which can be real or simulated. Special attention has been paid to see the impact of few consumption data in the results. A correction has to be made in the results for those situations when only the aggregate monthly or weekly consumption is available for analysis. From heat and electricity consumption data, a Matlab/Simulink model is used to calculate the amount of fuel needed so that the SOFC-CHP system can meet the demand, the amount of thermal energy that should be provided by an additional system (a conventional condensing boiler), as well as the electrical energy to be imported or exported from the electricity grid. The annual results are extrapolated to a time horizon of 10 years, to validate the economic viability of the project. Different operation modes (disconnected or connected to power grid) and operation strategies (heat-driven, power-driven, maximum-driven) of the SOFC-CHP system are analyzed in buildings of the Universitat Politècnica de Catalunya with varied heat-to-power 4 Memòria ratios, to determine the strategy that best suits each case. The results show that the high initial investment is one of the main obstacles to obtain a return on the investment in a reasonable time. However, the cogeneration system is economically viable in some of the studied cases, especially if the building has a heat to power ratio greater than one. The evolution of energy prices also greatly influences in the viability of the project. As for the operation strategies, those following maximum demand and those following electricity demand offer better results than the strategy that follows the thermal demand, because the former cases use the fuel cell throughout the year and can take more advantage of cogeneration.